1. Field of the Invention
The present invention relates generally to a code division multiple access (CDMA) mobile communications system and, more particularly, to a method for providing a free data service and a charging data service.
2. Description of the Related Art
In a CDMA mobile communications system, it is generally required for a base station to assign at least one orthogonal code for data communications to each of a plurality of mobile stations that request a data service. User data, such as voice signal and packet data, are communicated on dedicated channels that are separately established between the base station and each individual mobile station.
For that reason, in the related art CDMA communications system, the base station has to separately assign dedicated channels to each individual mobile station in order to communicate the same data (e.g., packet data) to each of the multiple mobile stations.
In a case where the identical data supplied by the system is free information available at any time at a plurality of mobile stations, the related art utilizes dedicated channels separately assigned to each of the mobile stations is a very inefficient method that requires unnecessary communication path and results in deterioration of data rate. It is therefore possible for the base station to assign a channel resource efficiently by using a specified channel assigned to send free information to the multiple mobile stations. This enables a plurality of subscribers to be served with free data service of small quantity, such as daily weather and stock information, through terminals at any time.
On the other hand, when the data supplied by the system is free information of large quantity, such as Internet services and the like, the base station has to send charging data only to the mobile stations that request the charging data service. And, the mobile stations receiving the charging data services must send billing information to the base station. For this procedure, there is a need of separately establishing and assigning forward and reverse link channels for data communications between the base station and the individual mobile stations that request the charging data service.
It is, therefore, an object of the present invention to provide a method for providing a charging data service and a free data service using channels efficiently assigned in a CDMA mobile communications system.
It is another object of the present invention to provide a method for providing a free data service in a CDMA mobile communications system, in which a base station sends information about a free data channel to a plurality of mobile stations on a common channel and then sending specified free data to the plural mobile stations on the free data channel.
It is further another object of the present invention to provide a method for providing a free data service in a CDMA mobile communications system, in which a mobile station demodulates a common channel received from a base station to detect information about a free data channel, demodulating the free data channel received from the base station according to the information about the free data channel and receiving the corresponding free data.
It is still further another object of the present invention to provide a method for providing a charging data service in a CDMA mobile communications system, in which a base station sends a first charging data channel information to a plurality of mobile stations on a common channel, assigning the charging data channels upon receiving a charging data service request message from a specified mobile station, sending a second charging data channel information to the mobile station requesting the charging data channel service on the common channel, and sending the corresponding charging data to the mobile station through the corresponding charging data channel upon receiving a service request confirm message from the mobile station.
It is still further another object of the present invention to provide a method for providing a charging data service in a CDMA mobile communications system, in which a mobile station demodulates a first charging data channel information on a common channel, sending the type of desired charging data and an ID code of its own to a base station through an access channel to request the charging data service, detecting a second charging data channel information on the common channel, sending a charging data service request confirm message to the base station on the access channel, and receiving the specified charging data on the corresponding charging data channels assigned thereto.
To achieve the above objects, there is provided a method for providing a data service in a CDMA communications system including the steps of: sending, at a base station, information about a free data channel to a plurality of mobile stations on the a common channel; and sending, at the base station, specified free data to the plural mobile stations on the free data channel.
According to another embodiment of the present invention, there is provided a method for providing a data service in a CDMA communications system including the steps of: demodulating, at a mobile station, a common channel received from a base station to detect information about a free data channel; and demodulating, at the mobile station, the free data channel received from the base station according to the information about the free data channel and receiving the corresponding free data.
According to further another embodiment of the present invention, there is provided a method for providing a data service in a CDMA communications system includes the steps of: (a) sending, at a base station, first charging data channel information to a plurality of mobile stations on a common channel; (b) receiving, at the base station, a charging data service request message from the specified mobile station; (c) assigning, at the base station, charging data channels and sending second charging data channel information to the mobile station on the common channel; and (d) sending, at the base station, specified charging data to the mobile station on the charging data channels upon receiving a service request confirm message from the mobile station.
According to still further another embodiment of the present invention, there is provided a method for providing a data service in a CDMA communications system including the steps of: (a) demodulating, at a mobile station, first charging data channel information on a common channel; (b) sending, at the mobile station, the type of charging data desired and an ID code of its own to a base station on an access channel and sending a charging data service request message to the base station; (c) detecting, at the mobile station, second charging data channel information on the common channel and sending a charging data service request confirm message to the base station; and (d) receiving, at the mobile station, the specified charging data on charging data channels assigned.